You might think you’re ready for the Mirror Universe version of Philippa Georgiou on Star Trek: Discovery, but you’re really not. The upcoming episode of Discovery, featuring Michelle Yeoh’s triumphant return to the Trek universe is called “Vaulting Ambition,” and it’s going to be explosive. Longtime fans haven’t seen an evil version of a good Star Trek character like this, since, well, pretty much ever.

Spoilers for Star Trek: Discovery* episodes 1-10, But NO SPOILERS For episode 11.

Evil versions of familiar Star Trek characters are as old as Star Trek itself. The fourth ever aired Trek episode was called “The Enemy Within,” which featured an evil version of Captain Kirk emerging from his “good self.” To be clear, this wasn’t a Mirror Universe episode (there’s only one of those in the classic series) but it does establish Trek’s long obsession with bad versions of the heroic regular cast. From Spock’s beard in “Mirror, Mirror,” to the all-evil versions of the Enterprise crew in 2005’s “In a Mirror, Darkly,” this optimistic and sunny sci-fi franchise has had an obsession with the dark side that rivals Star Wars.

Still, Discovery’s dive in the Mirror Universe is metaphysically a little more serious than previous forays into this realm. Unlike other alternate realities in science fiction, the Mirror Universe doesn’t seem hinge on an alternate outcome of one event in human history. Instead, the implications of the 2005 Enterprise two-parter seem to indicate the point of divergence goes back really, really far. Meaning, these aren’t just slightly parallel versions of people, but truly, their polar opposites. And the last time Trek had attempted a flip this as big as Emperor Georgiou was probably with Kira on Deep Space Nine

In the DS9 episode “Crossover,” the heroic Major Kira came face to face with her evil self, Intendant Kira, the ruler of the space station Terok Nor in the Mirror Universe. Thematically, the idea here is similar to all of Trek’s evil doppelganger stories: yes this character is totally evil, but there’s something in the character that is vaguely reminiscent of their good self. In Deep Space Nine, the Kira split was interesting, but perhaps not as nuanced as the approach Discovery is taking.

Burnham meets the Mirror Georgiou in 'Vaulting Ambition.'

Which is why Yeoh’s Emperor Georgiou is the riskiest and most daring plot development on Discovery yet. She’s not the snarling evil Archer from Enterprise, nor is she the coquettish Intendant Kira. Emperor Georgiou is straight-up merciless. But, like her Starfleet counterpart, she is in charge and believably so.

But will there be more than just frightening villainy from this storyline? After “Vaulting Ambition” airs, there are three episodes left in the first season, meaning there’s still plenty of time for a lot to happen. As Captain Kirk once said, “I want the impossible checked out too!” and if Discovery has taught Trekkies anything, it’s to expect the unexpected, and perhaps, even the impossible.